For the high power microscopes and student ones, you have the stage, stage clip, eyepiece, focus knob, and the body. For just the high power ones(in addition), you have, light source and different zooms. These work well for observing small specimens. For the student microscope, you have the mirror, and the knob. The mirror to provide light, and the knob to adjust the light. For the pieces in common, the stage holds the slide and the specimen. The clip makes sure they don't go anywhere. The eyepiece lets you look through and zoom in on the specimen. The body, holds everything together, and the focus knob focuses the specimen.